Quickie Reverb Time Calculator

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This quickie reverb time calculator can give you a fast indication of how much trouble you may be in with your current room design. This is a simplified rectangular room in this calculation, and should only be considered a first order approximation to tell you what magnitude of acoustical problem you can expect. We've provided the 2kHz calculation, as it's the critical speech intelligibility band. This calculator won't tell you what happens throughout the entire sound spectrum, as that takes a great deal more calculation, and requires a substantial amount of information regarding the room materials and construction details. You wouldn't want to base the acoustical treatment selection entirely on this calculator as you could still end up with other serious acoustic problems, such as flutter echoes, focusing etc. This is intended primarily as a guide to the relationship between room size, typical room finishes and reverb time. For public assembly spaces, life safety paging system applications, and other areas where speech intelligibility is a critical issue, a thorough acoustical evaluation should performed.

This is the 2kHz reverb time that you would expect in an unoccupied, unfurnished room with concrete or GWB walls and ceiling and a tile or concrete floor

This is the 2kHz reverb time you would expect in an unoccupied, unfurnished room with concrete or GWB walls, ceiling tile, and carpet

in Seconds

in Seconds

If the 2kHz reverberation time values are greater than the target values shown below, you will likely have a speech intelligibility problem. These are the 2kHz target values for reverberation time for each of these applications.

Classroom for hearing impaired accessibility 0.5 seconds

Church or theatre for speech/amplified music 1.0 seconds

Church or theatre for traditional music 1.5 - 1.8 seconds

Meeting Rooms 0.6 - 0.8 seconds

Large Convention facility 1.5 seconds

Gymnasium for teaching 1.5 - 1.8 seconds

Industrial Buildings 2.0 - 2.5 seconds

Small arena (500 -2000 seats) 2.0 seconds

Large arena (2000+ seats) 2.75 seconds

This information is provided with no warranty of its accuracy, or applicability, and any use made of this information is done so at the sole risk of the user.